</body>
<style>
   h1{
       color: blue;
       font-size: 12px;

    }
    #hi{
        color: red;
    }
    .hello{
        color: seagreen;
    }
</style>
<h1>
    你好呀🙌
</h1>
<h1 id="hi">你不好呀😜</h1>
<h1 class="hello">你一点都不好呀✌</h1>
<style>
    h1{
        border: seagreen;
        border-radius: 10px;
        padding: 15px;
        padding: 15px 30px;
        padding-left: 100px;
        margin: 50px;
        margin: 50px 100px;
        margin-left: 200px;
        margin-right: 200px;
    }
</style>

<h1>你好呀😍</h1>
   